This invention relates to oil well service rigs for servicing oil and gas wells. Such service rigs are used in oil wells for cleaning, to bail, to remove sand, to swab through tubing, to remove tubing, and for other maintenance and repair jobs.
An oil well, as other mechanical contrivances, requires maintenance and repair from time to time. This is frequently provided by means of an oil well service rig. However, conventional rigs tend to be expensive and require several men to operate same. Because of this, such rigs are not always readily available and the resulting down time can mean days and even weeks of lost oil well production. The situation has become particularly acute at the present time because of the oil shortage whereby it has become desirable to rehabilitate a number of oil and gas wells to improve, or to place same in, production as requirements dictate. Thus there is a need which exists and has existed, in fact, for a number of years for an oil well service rig which is reasonably inexpensive to purchase and operate and which can be conveniently operated by the single individual.
Concerning cooperation of hydraulic motor for operating a reel, this is disclosed in U.S. Pat. No. 3,887,163 to C. J. Prange. However the operation of components involved is different from that involved in the instant invention.
With reference to the gear box arrangement as disclosed herein, devices showing gear trains which can be placed in different arrangements for operating multiple output shafts are shown in the patents to Falk et al U.S. Pat. No. 2,943,504, to Varcoe U.S. Pat. No. 2,527,281, to Van der Bleek et al U.S. Pat. No. 504,289 and a German Pat. No. 1,095,700. However such arrangements are directed to different types of gear shifts that are not involved in the instant invention.
With reference to the use of a disc of a central drum for braking purposes, attention is invited to the U.S. patents to Hannay et al, U.S. Pat. No. 2,906,472, to M. Maroshick, U.S. Pat. No. 2,593,045, to D. D. Price, U.S. Pat. No. 3,599,974, to H. J. Mase, U.S. Pat. No. 666,852, to to L. M. de Kanski et al, U.S. Pat. No. 2,605,056, to R. W. Goode, U.S. Pat. No. 2,939,647, and to E. W. Reynolds, U.S. Pat. No. 2,571,061. However none of the above patents discloses the combination of utilizing a hydraulic disc type brake as taught in the instant invention.